Conventional broadcast equipment 101 is described as follows with reference to drawings.
FIG. 7 is a block diagram of conventional broadcast equipment 101, which includes antenna 102, broadcast receiving module 103, and display unit 104. Broadcast receiving module 103 includes receiver 105, demodulator 106 connected to the output of receiver 105, and signal processor 107 connected to the output of demodulator 106. Receiver 105 selects the signal of a certain channel from the signals of a plurality of channels received by antenna 102. Receiver 105, demodulator 106, and signal processor 107 are further connected to controller 108, which is also connected to input keys 111 and storage 112 including information of each channel.
Broadcast receiving module 103 of conventional type operates as follows.
In a case where the signal of the channel selected by receiver 105 is set to be the signal of a channel N (N is a natural number), when the user pushes a “next channel” button on input keys 111, controller 108 detects the signal coming from input keys 111. Controller 108 then reads from storage 112 the information of a first channel, which is a channel N+1 (or N−1) and sets the signal selected by receiver 105 to the signal of the first channel, based on the information of the first channel. Controller 108 then sets the channel of the signal to be demodulated by demodulator 106 to the first channel and determines whether the demodulated signal of the first channel demodulated by demodulator 106 contains a broadcast signal or not. The first channel is determined to be viewable or not in this manner.
When the demodulated signal of the first channel is determined to contain a broadcast signal, controller 108 controls signal processor 107 to process the demodulated signal of the first channel. On the other hand, when the demodulated signal of the first channel is determined not to contain a broadcast signal, controller 108 reads from storage 112 the information of a second channel, which is a channel N+2 (or N−2) and performs the same processes as those for the first channel. Thus, controller 108 repeats these processes until it determines that a certain demodulated signal contains a broadcast signal, that is, until a viewable channel is specified.
A related art of the present invention is Japanese Patent Unexamined Publication No. 2003-333441.
In a conventional broadcast receiving module like this, however, controller 108 determines whether the first channel is viewable or not based on whether the demodulated signal of the first channel contains a broadcast signal or not. Therefore, controller 108 can determine whether the first channel is viewable or not only after demodulator 106 completes the demodulation. This makes it time-consuming to specify a viewable channel.